This project aims to survey stink bugs and natural enemies in North Carolina soybeans. The threat of stink bug damage to soybean production has been increasing in multiple NC field crops over the past several years. We do not understand what environmental or crop patterns are driving this change. Moreover, the last comprehensive statewide survey of stink bugs in soybean was conducted several decades ago. As a result, we do not understand how the distribution of stink bug species vary at the field, farm, or regional level across the state. Generating this information is important because susceptibility to common insecticides varies among species and, in turn, efficacy of spray decisions. Preservation of natural enemies that are predators of stink bugs and other pests is another component of sustainable soybean production systems. We do know that several stink bug egg parasitoids are important predators of these pests, however, we do not know how common they are across the state. To address this knowledge gap, this project proposes an on-farm survey of stink bugs and associated natural enemies in soybean from the mountains to the coast. Results from this survey will complement several other NC State projects focused on stink bug management. Together, our collective efforts will help guide extension efforts focused on regionally specific scouting and pesticide recommendations.

1. To quantify stink bug species composition and abundance in reproductive soybean across the state.
2. To survey stink bug egg parasitoids species and parasitism rates.

This project will produces a baseline data on the stink bug species complex diversity and abundance across three ecological regions of the state. Particularly, objective 1 will document where stink bugs are most abundant before overwintering across the state. Also, it will be a baseline record to compare the stink bugs communities over time and space across the state. Objective 2 helps to understand the egg parasitoids species diversity and rate of parasitism at the field level. In long term, results of egg parasitoids species composition and rate of egg parasitism would be a valuable inputs for potential biological management of stink bugs. These results will be linked to our ongoing pyrethroid resistance bioassays (particularly bifenthrin) to help farmers make better management decision depending on the common species in their area and potential resistance issues present.

The diversity of stink bug species and the severity of damage differs across North Carolina. For example, brown marmorated stink bugs are commonly found in Piedmont soybeans and brown stink bugs are one dominant species in the coastal plain. These coarse species distributions give farmers and crop consultants general guidelines about which species should be in soybean. A more comprehensive survey will help improve our extension recommendations for different NC soybean production areas. The first objective of this project will document the stink bug abundance and species composition using sweep samples in reproductive stage soybeans across the state. For the second objective, we will use the preserved sweep samples to identify natural enemies present in the crop. Together, we will generate a better understanding of field and regional sink bug differences.